Donald Trump announced Tuesday he would use a federal anti-terrorism surveillance law as a tool to force Mexico to pay for the border wall he has pledged to build on the U.S.’s southern border. Trump outlined the steps his administration would undertake to compel Mexico to pay the U.S. “$5-10 billion” to fund a border wall in a memo his campaign released Tuesday morning – a plan that relies largely on threatening to bar undocumented Mexican immigrants in the United States from wiring money to relatives in Mexico. Using a broad interpretation of the post-9/11 USA Patriot Act, Trump writes in the memo that he would threaten to issue new regulations that would compel money transfer companies like Western Union to verify a client’s identity and legal status before authorizing a wire transfer. “Good luck with that,” President Barack Obama said Tuesday when asked about the plan during an appearance in the White House briefing room. He said the plan was “impractical” with enormous implications for the Mexican economy. “(It) actually sends more immigrants north because they can’t find jobs back in Mexico,” Obama said. Trump’s memo also lays out other potential tactics to force Mexico to shell out for the border wall that Trump first laid out in the immigration policy paper he released in August, including imposing tariffs on imports from Mexico, canceling Mexican nationals’ visas and raising visa fees. “We have the moral high ground here, and all the leverage,” the memo said. “It is time we use it in order to ‘Make America Great Again.’” The immigration plan Trump released in August also homed in on money transfers to compel Mexico to pay for the wall, vowing to “impound all remittance payments derived from illegal wages.” Trump released that policy paper after working closely with Sen. Jeff Sessions, the Alabama Republican who months later endorsed Trump.